Road-paving block



to g sep 1927 H. H. DUKE Rom) PAVING BLOCK Original Filed Feb. 4, 1924 Patented Sept. 20, 1927.

UNITED. STATES nnnonn HILL DUKE, or nooKnALn, SIGNOB. vor ONE-HALF r0 JOSEPH wnnns, AUSTRALIA.

PATENT OFFICE,

SYDNEY, NEW SOUTH WALES, AUSTRALIA, AS- HARRIS, 0F BRIGHTONLE SANDS, NEW SOUTH Roan-ravine BLOCK.

Application filed February 4, 1924, Serial No. 690,670. Renewed March 28, 1927.

This invention relates to road paving blocks of the type which have hitherto been constructed either wholly or partly of rubber strengthened and toughened by the admixture of various fillersand vulcanizing ingredients.

Rubber, previous to 'this invention has been generally applied to road construction in one of three ways (1) in the form of sheets and mixedwith other materials (2) in the form of individual blocks, the rubber or rubber compound being aflixed in various ways to foundations of concrete or similar material, or (3) in the form of solid rubber blocks similar in size to the well-known wood blocks, having a wearing surface of better quality rubber than the body of the block. a This invention refers more particularly to the third type of pavement and the object of the invention is to provide an improved block which will have all the advantages of struct and a solid rubber'block, i. e. resiliency, tough surface, ability to stand u to hard wear'an long life, butwhi'ch will he cheaper to conlighter in weight. In. the accompanying drawin there is illustrated diagrammatically a block constructed according to the preferred form of the invention. a

The invention consists in formin fthg' rubber, the cork-being ground to about" the ,j

canizingiingredients in well known propor tlons so'that when it is vulcamzed under size of a pea and being combined with sufli cient rubber together with well known v'ul ressure a ,compact and tough block is ormed'. The proportions of corkand rubher are approximately three parts cork to d road way will be a continuous and; homo 'of approximately cork, one partof rubber, and vulcan zing 1ngredientsf, vulcanized to sure ointoa compact an waysin the tread surface of the block, a relatively thicklayerof rubber vulcanized to the tread surface. of the block, and -relativelythin luyerf of rubberfvulcanizdl The upper surface is formed with rooyes or channels 2 to receive a wearing ayer 3 about inch to inch thick of high grade tread? rubber which is vulcanized and 4a keyed to block by the grooves or channels2. The other sides of the block are faced with a thin layer 4 of rubber so as to render the whole block impervious to moisture.

The block may be strengthened by the ad-v dition of some flexible re-inforcemen't such as canvas or wire-netting or similar reinforcement.

The underside of the block may be fluted 1 as at 5 so that when it is laid on the concrete base any water which may percolate through may get away. It is obvious that the blocks ma be moulded in any desired shape in accor ance with the particular'purpose for which it is and adjoining sides which may be grooved,

are coated with pitch or the likeso that the geneous mass,

For a cheaper. I

stituted for the cork ingredient".

I. claim:- I A paving block which comprises a mixture Z0,

three parts of gunning-1 each of the othersurfaces oithe block sawdust may i 

